When Michele Harrison turned 40, she decided to sell her New York City apartment to buy a bigger one. She could afford it after laser-focusing on her career, working late nights as a single woman, traveling constantly for ad agencies and then in marketing at ESPN.
While in the process of selling, she temporarily moved in with her aunt in the suburbs. She began to notice how nice it was to see green grass and have room to breathe. She quit her job and swapped her hard-charging big-city existence for the wide-open panoramas of Colorado.
One of the first tasks was a routine checkup with a gynecologist. By this time, Harrison was 41. At her appointment, the doctor got right to the point: “Do you want to have a baby?”
“I was like, ‘I have no idea,’” says Harrison. “I was in shock. I don’t think I ever really thought about having kids or about how old I was, because I had been so focused on my career.”
Her doctor referred her to the Colorado Center for Reproductive Medicine (CCRM), which has a reputation for helping “older” women get pregnant. When it comes to fertility, 35 is the tipping point that medicine calls AMA, or “advanced maternal age.” It’s not an arbitrary designation. A woman’s fertility starts to wane around age 32, and the decline picks up speed by 37, according to the American College of Obstetricians and Gynecologists.
“If you want to freeze your eggs,” she was told, “now is the time.” She joined the growing number of women trying to delay biology. More than 7,000 US women froze their eggs in 2016, up from fewer than 500 in 2009.
“I thought, ‘Why don’t I just do this as insurance so I don’t miss the window?’” she says.
In truth, the window was already nearly closed. Fertility specialists encourage women who want to freeze their eggs to do so in their late 20s and early 30s, when they still have a healthy supply. Midway through gestation, a female fetus has 3 million eggs in each ovary. At birth, that number has dropped to 500,000. By puberty, a girl is down to 150,000 per ovary. At menopause that woman will have very few eggs left, and many will be riddled with genetic errors that occur with aging. The more DNA damage, the more likely an egg or embryo is to result in miscarriage, chromosomal abnormality, or no pregnancy at all.
It’s not clear why girls are born with more eggs than they could possibly ever use. Nor is it clear why the numbers drop so precipitously over the years, although genes seem to play a role. What is certain is that no one has figured out how to definitively extend fertility—yet.
Egg freezing is the closest we’ve come. Hyperstimulate a woman’s ovaries with hormone injections to produce more than the single egg released in a typical menstrual cycle. Retrieve those eggs with a needle in a quick surgical procedure. Then individually flash-freeze them using a method called vitrification, designed to prevent the formation of ice crystals, and immerse them in liquid nitrogen until they’re ready to be thawed. Ta-da—babies on ice!